Question: Name the nuclear weapons test with the lowest explosive energy equivalent whose country of origin is soviet union?
Paraphrase: What nuclear weapons test has the lowest explosive energy equivalent in the Soviet Union?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q210112 . ?ent wdt:P2145 ?obj . ?ent wdt:P495 wd:Q15180} ORDER BY ASC(?obj)LIMIT 5 
Answer: Totskoye nuclear exercise